Telecommunications services apparatus

ABSTRACT

In a telephone system, such as a mobile telephone system capable of handling text messages, address signals for telephone communication may be in one of first and second signal formats such as dialled numeric signals and alphanumeric signals. An SMS Router ( 10 ) can distinguish between the numeric and alphanumeric signals, and directs numeric address signals to a short message service centre SMSC ( 18 ). The alphanumeric address signals may instead be re-routed on the basis of stored information, such as in a database ( 14 ), for example directly to an SMS Host ( 16 ). Alternatively, the alphanumeric address signals can be converted by the SMS Router ( 10 ) to numeric signals, on the basis of the stored information, and then directed to the SMSC ( 18 ).

This invention relates to telecommunications services apparatus for usewith a telephone system, in particular but not exclusively to a mobiletelephone system capable of handling text messaging.

Text messaging is established as a popular and effective means ofcommunication for users of mobile telephones. The Short Message Services(SMS) of the GSM mobile telephony system provide such a text messagingfacility, and support for the composition, transmission and reception ofShort Messages is present in the majority of mobile terminals. Textmessaging requires alphanumeric entry using the standardised Man MachineInterface (MMI) of the mobile handset, and also requires that themessage be addressed to the desired recipient. The destination addressfor the message may typically be specified either by entering a MobileStation ISDN number (MSISDN) which is the mobile telephone number of thedesired recipient, or by selecting an entry from the handset's addressbook which already has the desired MSISDN pre-programmed in. The addressbook normally provides the MSISDN by using alphanumeric look-up of aname.

The SMS mechanism was originally defined for mobile to mobile textmessaging, but has been extended to permit communication between mobilesand fixed entities in the network known as SMS Hosts. SMS Hosts aretypically used for receiving the results of SMS voting events, ortransmitting messages such as football results in bulk to users whosubscribe to a football service for example. SMS Hosts are responsiblefor an increasing proportion of SMS traffic.

One of the features of SMS is that an identifier corresponding to thesender's identity is always transmitted to the recipient. It may not beoptionally withheld by the sender. This Calling Line Identity (CLI) isnormally sent and may be displayed in the form of an MSISDN, though mosthandsets will translate this to an alphanumeric name if there is acorresponding MSISDN entry in the handset's address book. This providesease of recognition of the sender, without the recipient having toremember telephone numbers. The mobile CLI feature is analagous to theCLI facility available on fixed networks. Another benefit of receivingCLI is that a reply to the message is more easily achieved, withouthaving to explicitly specify the return address. The MMI for mobilehandsets defines “Reply” as a standard feature.

As an alternative to transmission of the CLI identifier as an MSISDN,the GSM system also supports the transmission of a short alphanumericvalue or name instead. Support for reception and correct display of analphanumeric CLI is almost universally available on recent mobiletelephones.

Unfortunately an alphanumeric CLI is not generally usable with the“Reply” function of a handset. Attempts to reply to an alphanumericaddress will currently be rejected by the network because the shortmessage service centre (SMSC) has no means to identify the home locationregister (HLR) which should be queried to look up the InternationalMobile Subscriber Identity (IMSI) of the desired recipient from thealphanumeric identifier. Even if the correct HLR could be identified bythe SMSC, the HLR would normally only capable of looking up an IMSI froman MSISDN. The SMSC therefore rejects the message as undeliverable.

This is a problem for networks and service providers who would like touse alphanumeric identifiers both to promote their brands, and to ensurethat recipients are aware of the message source. In this regard,alphanumeric names are much preferable to an MSISDN number, especiallyas the MSISDN CLI of an SMS Host service is unlikely to match an entryin the recipient's address book.

Currently for messages sent by SMS Hosts, operators and serviceproviders have a choice. They can choose to use an MSISDN as a CLIthereby giving the recipient the option to reply, or they can elect tosend an alphanumeric CLI accepting that the recipient cannot reply.

It is an aim of at least an embodiment of the present invention to solvethis problem, and to allow the standard “Reply” function of a mobilehandset to work successfully for messages which have an alphanumericCLI, without any changes being required in the handset.

One aspect of the invention provides telecommunications servicesapparatus for use with a telephone system in which address signalsassociated with telephone communication may be in one of first andsecond signal formats, wherein the first signal format is recognisableby communication enabling equipment in the telephone system, theapparatus comprising receiving and directing means for receiving theaddress signals and being operable to distinguish between addresssignals in the first and second formats, to direct the address signalsin the first format to the communication enabling equipment, and tore-route the address signals in the second format on the basis of storedinformation accessible to the receiving and directing means.

Another aspect of the invention provides telecommunications servicesapparatus for use with a telephone system in which address signalsassociated with telephone communication may be in one of first andsecond signal formats, wherein the first signal format is recognisableby communication enabling equipment in the telephone system, theapparatus comprising receiving and directing means for receiving theaddress signals and being operable to distinguish between addresssignals in the first and second formats, to direct the signals in thefirst format to the communication enabling equipment, and to convert theaddress signals in the second format into address signals in the firstformat on the basis of information accessible to the receiving anddirecting means prior to directing the converted signals to thecommunication enabling equipment.

In future, as more handsets gain the ability to enter an alphanumericaddress, the present invention will support the use of alphanumericdestination addresses on mobile initiated messages as well as onreplies. In addition to being able to send mobile initiated messageswith alphanumeric destination addresses to SMS Hosts, mobile networksmay offer users the option to adopt a personal alphanumeric identity asan alias for their MSISDN. These identities might need to be uniqueacross the whole network, or unique within a closed user-group orcommunity. Messages could then be sent to other users by using theiralphanumeric address instead of a destination telephone number.

The Short Message Services of GSM define signalling messages within theMobile Application Protocol (MAP) for transferring the Short Message inMobile Originated (MO) mode between the mobile handset and the ShortMessage Service Centre and in Mobile Terminated (MT) mode between theShort Message Service Centre and the mobile handset.

There are four address identifiers which are relevant to Short Messagetransmission, and these are—

-   -   The MSISDN of the sender (his CLI)    -   The MSISDN of the recipient (the destination address)    -   The IMSI of the recipient (used by the network to deliver the        message to the correct phone)    -   The Short Message Service Centre address.

When a Short Message is sent from one mobile to another, it normallypasses through an SMSC of the home network of the sending subscriber,even when the sending subscriber is roaming on another network. Themessage arrives at the SMSC in Mobile Originated mode, is converted toMobile Terminated mode by the SMSC, and is then delivered to thedestination. The MAP messages which support SMS transmission have threefields which are used to carry the four address identifiers listedabove. The MAP address fields are called DA (Destination Address), OA(Originating Address) and UI (User Information.) They are used as shownin Table 1. TABLE 1 MAP LEVEL field population

Table 1 shows the transpositions of the address identifiers which occuras the SMSC converts the incoming MO message type into an outgoing MTmessage type. The IMSI is obtained by looking up the destination MSISDNnumber in the destination network's home location register (HLR). Thisis the root cause of the failure of replies to Short Messages with analphanumeric CLI. If the MO reply from the mobile uses an alphanumericidentifier as its destination address, then when the SMSC attempts todetermine which HLR to use to look up the IMSI of the recipient, itfinds that the alphanumeric identifier is not formatted according to thestandard MSISDN international numbering plan, and it is therefore unableto deduce the identity of the destination network. It is consequentlyunable to query an HLR to obtain an IMSI for delivery.

The present invention addresses the above problem by interceptingmessages which have alphanumeric destination addresses before they reachthe SMSC. If the solution is installed in the network of Operator A thenit will be operative for all of Operator A's subscribers even when theyare roaming on other networks. By appropriate signalling means (wellknown in telecommunication networks). Short Messages destined forOperator A's SMSC are routed via one or more equipments which implementthe present invention. Short Messages which do not have an alphanumericdestination address are forwarded on transparently by these equipmentsto the SMSC for normal handling, while messages which do have analphanumeric destination address are handled differently.

In one preferred implementation these messages are modified to convertthe alphanumeric destination address carried within the User Informationfield of the MO MAP message into an MSISDN by means of a look-up tableor database. The Short Message may then be forwarded to the SMSC fornormal handling. In another preferred implementation, Short Messageswith alphanumeric destination addresses which correspond to theaddresses of SMS Hosts of Operator A's network, are delivered over acommunication link to the SMS Host without passing through the SMSC.

Short Messages which have an alphanumeric destination address which isnot matched in the look-up table or database are treated specially,either by discarding the message or by forwarding the message to adefault destination, and in either case optionally informing the senderof the delivery failure.

By means of interpretation of the alphanumeric destination address usinga look-up table or database, the problem of replying to messages withalphanumeric destination addresses is solved. This also allows messagesthat are initiated from mobile handsets with an alphanumeric destinationaddress, rather than simply replied, to be delivered successfully by thenetwork if and when support for alphanumeric address entry is providedin mobile handsets.

Additionally, equipment may be provided in the network which wouldoptionally modify the parameters of an initiated call or communication,so that for white-listed customers their MSISDN CLI, as generated bycurrent handsets, would be replaced by a meaningful alphanumeric CLI fordisplay at the recipient's terminal. This would then allow mobilecustomers to have their selected name presented at receiving terminalswithout requiring the sending terminal to have the capability to supportalphanumeric CLI generation.

Similar techniques to those described above for Short Messages can alsobe applied to voice calls, and other types of call. Once support isprovided in handsets for initiation of calls with alphanumeric CLIand/or alphanumeric destination address entry, then the benefits ofsending a call or communication to a meaningful name rather than anumber, or receiving a meaningful CLI for any type of call orcommunication, can be realised. One of the reasons that the Internet isso successful is that the addressing scheme uses indirection andalphanumeric addresses. The Internet URL of a desired company site canusually be inferred from the company name.

In co-pending International Patent Application No. PCT/GB02/01724,architecture is disclosed for filtering Short Messages, that selectivelyroutes Short Messages either directly to their destination or via anSMSC according to message characteristics. The equipment location in thenetwork and the Short Message content examination required to do thefiltering have similarities to the preferred embodiment of the presentinvention.

The functionality and operation of home location registers (HLRs) inmodern mobile networks is well described by the international standards.Although HLRs may implement proprietary features, the signallingmessages which are required to support voice-call and short messagereception and transmission are fully defined. It is also known that HLRfunctionality can be divided amongst multiple physical equipments. Theseequipments are normally geographically diverse and physically similar.

The use of SMS Hosts is also well known. SMS Hosts are usually connectedto a mobile network via the Short Message Service Centre (SMSC), usingone of a number of standard protocols. Many networks support thereception and transmission of large quantities of short messages byattached SMS Hosts.

It is also known that methods exist for accessing these SMS Hosts fromother networks, albeit with throughput restrictions. These methodsovercome earlier addressing limitations by assigning the SMS Hosts arange of mobile telephone numbers so that messages can be addressed tothem as though they were mobile handsets. This permits access to the SMSHosts from any mobile network. This technique has become known asvirtual mobile.

Signalling messages can be routed within a network using SignallingTransfer Points (STPs). These have the capabilities to direct messagesto preferred or secondary destinations according to an addressing schemewhich uses Global Titles. The MSISDN of the destination mobile telephoneor SMS Host has been used as the Global Title for routing ShortMessages. By manipulating the look-up tables within STPs it is possibleto control the routing of signalling messages through a network. STPscan also compensate for non availability of a signalling destination byusing secondary or tertiary routing addresses. Global titles can also beassigned to groups of equipments, with STPs used to distribute messagesto that title amongst the equipments.

The invention will now be described by way of example with reference tothe accompanying single figure drawing, FIG. 1. which shows a blockdiagram of an architecture for SMS alpha translation of MobileOriginated (MO) messages.

The preferred embodiment of the present invention uses a Telsis (RTM)SMS Router. manufactured by Telsis Limited. This equipment connects tothe mobile telephone network using well known and standardisedsignalling protocols including SS7 and TCP/IP. Using well knownsignalling routing techniques, the mobile network can arrange for ShortMessages directed to the network's SMSCs to be routed via the SMSRouter. Short Messages may then be forwarded to an SMSC from the SMSRouter. The SMS Routers are said to be in-line with the SMSC's messagereception.

In an alternative embodiment, the present invention uses a Telsis SMSRouter 10 as shown in FIG. 1. This equipment connects to the mobiletelephone network using well-known and standardised signalling protocolsincluding SS7 and TCP/IP. The SMS Router 10 is connected to have accessto a database 14, and also to an SMS Host 16, either directly or via theShort Message Service Centre (SMSC) 18 of the network.

By arranging for the SMSC number in a user's handset 20 to be changed,the mobile network can arrange for Mobile Originated Short Messages fromthis handset to be routed to the SMS Router 10. The SMS Router 10 maythen modify the SMSC address in the message and forward the message,causing the message to be onward routed to the SMSC 18. This embodimentis advantageous for rapid deployment of a solution without extensivemodifications to network routing. It is simply necessary for the ServiceCentre number in the handset 20 to be changed (either manually orremotely) to an address corresponding to the SMS Router 10, for therouter to have access to that user's mobile originated messages.

In a further embodiment, the invention is implemented in conjunctionwith a virtual mobile technique such that messages arriving from othernetworks may be arranged to pass through an SMS Router that implementsthe invention. This arrangement is particularly convenient when thevirtual mobile equipment itself comprises one or more SMS Routers. Thefunctionality of virtual mobile may then be extended according to thepresent invention, permitting messages with alpha addresses to bereceived from any network, and handled appropriately.

In any embodiment, the address of the SMS Router 10 may be a globaltitle which represents a group of SMS Routers, and the network may usewell-known mechanisms for address resolution to direct messages to anappropriate specific SMS Router. In this way, SMS Routing capacity canbe increased by adding more SMS Routers.

In any embodiment, the techniques for alphanumeric addressing asdescribed may be used not only for routing messages, but also forinvoking network services. For example, a Short Message sent to thealphanumeric address “HELP” could be directed to an SMS Router by way ofthe means described, and used to trigger the provision of assistance tothe user, for example by SMS.

The SMS Router 10 has the capability to rapidly examine and manipulatethe contents of MAP message fields and User Information within theprotocol data of the Short Message. By use of an internal look-up tableor an attached database 14, depending on the number of entries to bestored, the SMS Router 10 is capable of replacing alphanumeric CLIvalues in the UI field with corresponding MSISDNs obtained from thelook-up process. The look-up process preferably uses a hashing techniqueto minimise the storage required in the data table. Messages whicharrive with non-alphanumeric addresses may be forwarded to the SMSC 18transparently by the SMS Router 10.

Depending on the address determined as a result of the look-up, themessage may be forwarded to an SMSC with a translated destinationaddress, or may be passed to an addressed SMS Host over a communicationlink without passing via an SMSC. This has the advantage of reducingloading on the SMSC. The SMS Router is also capable of producingtransaction detail records which can be used for logging and/or billingpurposes.

Short Messages which do not have an alphanumeric destination address, asindicated by the address type parameter carried with the Short Message,are passed through to the SMSC transparently, while alphanumericaddresses may be modified. If desired the modification may beconditional upon a white-list so that only certain subscribers have thebenefit of this service.

When Short Messages having an alphanumeric destination address are notrecognised, they may either be rejected or sent to a defaultdestination, in either case, the caller may be informed of deliveryfailure, for example by voice message from the equipment.

In the description, the term SMS Host is used to mean an equipment, aservice or a service-provider which is capable of terminating an SMSMessage. The present invention therefore allows users to send a ShortMessage to a destination, such as a bank or airline for example, withoutneeding to know the telephone number, but instead by using thealphanumeric name or an abbreviation for the desired destination, whichmay represent for example a company, a service, a service-provider oreven an individual. The desired destination may be reached either via anSMSC or directly, either over SS7 or via another protocol, and eitherwithin the same network or in a different network. GLOSSARY CLI CallingLine Identity GPRS General Packet Radio Service, Enhancement to GSMmobile telephone system for transfer of packet data IMSI InternationalMobile Subscriber Identifier MAP Mobile Application Protocol MMI ManMachine Interface of the GSM handset MO Mobile Originated MSISDN MobileStation ISDN number MT Mobile Terminated PLMN Public Land Mobile NetworkSMS Short Message Service of the GSM mobile telephone system SMS HostEquipment for sourcing and sinking Short Messages for spec applicationsSMS Router Equipment which embodies the invention and filters andresponds certain signalling messages. SMSC Short Message Service CentreSS7 CCITT Signalling System no 7 STP Signalling Transfer Point TCP/IPTransmission Control Protocol/Internet Protocol. A well known inter dataprotocol. UI User Information URL Universal Resource Locator

1-14. (cancelled)
 15. Telecommunications services apparatus for use witha telephone system in which address signals associated with telephonecommunication may be in one of first and second signal formats, whereinthe first signal format is recognisable by communication enablingequipment in the telephone system, the apparatus comprising receivingand directing means for receiving the address signals and being operableto distinguish between address signals in the first and second formats,to direct the address signals in the first format to the communicationenabling equipment, and to re-route the address signals in the secondformat on the basis of stored information accessible to the receivingand directing means, wherein the telephone system is a mobile telephonesystem for sending and receiving message signals, wherein the firstsignal format comprises a sequence of dialled numeric signals, andwherein the second signal format comprises a sequence of alphanumericsignals.
 16. Apparatus according to claim 15, wherein the storedinformation is accessible from a means operable to identify a re-routingdestination from the address signals in the second format.
 17. Apparatusaccording to claim 16, wherein the means operable to identify are-routing destination comprises a look-up table.
 18. Apparatusaccording to claim 15, wherein the first signal format comprises mobilestation ISDN (MSISDN) signals.
 19. Apparatus according to claim 15,wherein the telephone system is a mobile telephone system for sendingand receiving text message signals.
 20. Apparatus according to claim 15,wherein, when received address signals in the second format are notrecognised, the attempted associated telephone communication isrejected.
 21. Apparatus according to claim 15, wherein, when receivedaddress signals in the second format are not recognised, the attemptedassociated telephone communication is directed to a default destination.22. Apparatus according to claim 20, wherein, when the received addresssignals in the second format are not recognised, the subscriberinitiating the attempted associated telephone communication is informedof delivery failure.
 23. Apparatus according to claim 15, whereinmessages may be received from any network using a virtual mobiletechnique.
 24. Apparatus according to claim 15, wherein processing ofaddress signals in the second format is conditional upon the subscriberinitiating the attempted telephone communication being on a white listof subscribers.
 25. Telecommunications services apparatus for use with atelephone system in which address signals associated with telephonecommunication may be in one of first and second signal formats, whereinthe first signal format is recognisable by communication enablingequipment in the telephone system, the apparatus comprising receivingand directing means for receiving the address signals and being operableto distinguish between address signals in the first and second formats,to direct the signals in the first format to the communication enablingequipment, and to convert the address signals in the second format intoaddress signals in the first format on the basis of informationaccessible to the receiving and directing means prior to directing theconverted signals to the communication enabling equipment, wherein thetelephone system is a mobile telephone system for sending and receivingmessage signals, wherein the first signal format comprises a sequence ofdialled numeric signals, and wherein the second signal format comprisesa sequence of alphanumeric signals.
 26. Apparatus according to claim 25,wherein the stored information is accessible from a means for providingcorrespondence between specific address signals in the first format andrespective address signals in the second format.
 27. Apparatus accordingto claim 26, wherein the means for providing correspondence comprises alook-up table.
 28. Apparatus according to claim 25, wherein the firstsignal format comprises mobile station ISDN (MSISDN) signals. 29.Apparatus according to claim 25, wherein the telephone system is amobile telephone system for sending and receiving text message signals.30. Apparatus according to claim 25, wherein, when received addresssignals in the second format are not recognised, the attemptedassociated telephone communication is rejected.
 31. Apparatus accordingto claim 25, wherein, when received address signals in the second formatare not recognised, the attempted associated telephone communication isdirected to a default destination.
 32. Apparatus according to claim 30,wherein, when the received address signals in the second format are notrecognised, the subscriber initiating the attempted associated telephonecommunication is informed of delivery failure.
 33. Apparatus accordingto claim 25, wherein messages may be received from any network using avirtual mobile technique.
 34. Apparatus according to claim 25, whereinprocessing of address signals in the second format is conditional uponthe subscriber initiating the attempted telephone communication being ona white list of subscribers.